To all of you trying to squeeze that extra little something out of the Crumble, boy do we have something for you!

Allow me to introduce the Big Fun, our aggressive trail, or maybe just “enduro” hardtail. This is our take on the trifecta known simply as “LLS”. Long. Low. Slack. We built this model around a proven geometry that’s ready to take on any trail you can throw at it, and then some. Build your bike with a 140mm fork for a solid trail rig, or mount a 160mm fork and push yourself to the limit. Big hardtails like this are truly so much fun!

The Big Fun borrows a ton of tech from our still-top-secret full suspension trail-duro bike, like a huge ZS44/ZS56 headtube, and custom drawn tubing for all the durability with none of the trail chatter.

All of this, built by hand in Saxony!

All Sour frame are now made in Germany, by us, right here in Saxony. Production pre-orders happen quarterly, but frames can be ordered at any moment of the year. With the exception of special orders, sizes, and frames, all orders are expected to have a 6-10 week delivery time.



Handmade Sour Bicycles CrMo frame featuring heat treated, multi-butted tubing

Our dropouts and designed in-house, in Dresden and have a replaceable derailleur hanger.

The seat clamp is designed in-house and is integrated into the frame. Should it ever fail, the frame can be professionally modified to use a traditional clamp.

By The Numbers

Headtube: ZS44/ZS56

Bottom bracket: 73mm BSA threaded

Rear spacing: 148x12mm Boost thru axle

Seatpost: 31.6mm diameter

Brake standard: IS2000 (ISO, more info here)

Recommended fork travel: 140mm – 160mm

Wheel size: 29“

Tire clearance: up to 2.6″

Bonus facts and features:

External cable routing for easy maintenance

Stealth dropper post routing

Two water bottles inside the frame

Fork Options

Marzzochi Z1 150mm, black

Fox 36, 29″, 150mm, Grip, 3 POS-ADJ, 44mm Offset, black

Dropper Posts:

Bike Yoke Revive 31.6mm 125/160/185mm


Bike Yoke Triggy, 22.2mm

Frame weights incl. powdercoating and small parts

Big Fun S = 2760g

Big Fun M = 2810g

Big Fun L = 2870g

Big Fun XL = 2970g

*Weights averaged with 3 frames per size (+/-50g)


Marzzochi Z1, 29″ = 2275g

Bike Yoke Revive 31,6mm 125mm = 475g

Bike Yoke Revive 31,6mm 160mm = 535g

Bike Yoke Revive 31,6mm 185mm = 575g

Included with your frame:

Frame only: Frame, derailleur hanger, derailleur hanger “dummy” hanger for singlespeed, rear thru axle

Frameset: Frame and fork, front and rear axle, and Acros headset